Children Exposed to Arsenic in Well Water Have Lower IQ Scores

April 22, 2014

A study by Columbia researchers has found that children from three school districts in Maine exposed to arsenic in drinking water experienced declines in intelligence.

This marks the first time that researchers have examined intelligence in connection with individual water arsenic exposures in the United States. Earlier studies in Bangladesh by the same team of researchers showed that exposure to arsenic in drinking water lowers child intelligence.

Joseph Graziano, professor of environmental health sciences at the Mailman School of Public Health, led the research in Maine districts where household wells were the predominant source for drinking water and cooking.

Water samples were taken at the point of entry into the home and at the kitchen sink. The researchers also considered drinking habits, length of residence in the home, well construction and use of filters.

On average, the study showed water arsenic levels that exceeded the maximum contaminant level guidelines of the World Health Organization and U.S. Environmental Protection Agency.

“Collectively, our work in Bangladesh and in Maine suggests that aspects of performance intelligence, particularly perceptual reasoning and working memory, are impacted by exposure to arsenic in drinking water,” said Graziano, who is also a professor of pharmacology at Columbia’s College of Physicians and Surgeons.

The findings, reported online in the journal "Environmental Health," showed that after adjusting for maternal IQ and education, characteristics of the home environment, school district and number of siblings, the exposed children showed a significant decline that may translate to problems in school, according to Gail Wasserman, the study’s first author and a professor of medical psychology in the Department of Psychiatry.

“Even though purchasing a standard filter at the hardware store is inadequate for treating well water, the good news is that there are steps one can take to ameliorate the situation,” said Graziano. He and other experts recommend installing a reverse osmosis system to alleviate the effects of waterborne arsenic.

A series of outreach programs are underway to educate families in the region.